ASTR101: Introduction to Astronomy

Unit 14: Extraterrestrial LifeIn this chapter, you will be introduced to our current thoughts on the
existence of life beyond the confines of earth. Drawing on our
understanding of the development of life on earth, we will speculate on
its existence elsewhere. We will look at the Drake equation, a formula
for estimating the number of technological civilizations that exist in
our galaxy now, and review the arguments over the existence of
extraterrestrial life.

Unit 14 Time Advisory
This unit should take approximately 4 hours to complete.

☐ Subunit 13.1: 1 hour

☐ Subunit 13.2: 1 hour

☐ Subunit 13.3: 1 hour

☐ Assignment: 1 hour

Unit14 Learning Outcomes
Upon successful completion of this unit, students will be able to:
- List the conditions thought to be necessary for life to exist in the
universe.
- List the terms of the Drake equation and make estimates as to the
values of each term.
- Compare the arguments for and against the existence of
extraterrestrial life.

Instructions: This reading discusses the finding of an extrasolar
planet within the habitable zone of its star. The discovery was
made by the Kepler observatory, whose mission is to hunt for
earth-sized alien planets in the habitable zone of their parent
star, where liquid water, and perhaps life, might be able to
exist.
Reading this article should take approximately 15 minutes.
Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

Instructions: If you find the search for extraterrestrial
intelligence fascinating, you may want to join in that effort. Here
is a link that explains how you can become involved. Look it over
for a few minutes and see if you are interested.
Studying this resource should take approximately 10 minutes.
Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

Instructions: This site describes the various terms in the Drake
equation. It also allows you to put in the values you think are
most appropriate for each term, and it will calculate what the
expected number of potentially communicating civilizations there are
in our galaxy.

Reading this article should take approximately 15 minutes.

Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

Instructions: This video is a very nice, balanced approach to the
question.
Watching this video should take approximately 5 minutes.
Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.

Instructions: When you have finished the entire unit, please
complete this assessment without referring to the readings. When
you are finished with the assessment, you can check your answers
against the Saylor Foundation’s “Unit 14 Assessment – Answer
Key” (PDF).

Instructions: The first third or so of this article is entitled
“Fermi’s Paradox (i.e., Where are They?)”. Be sure to read this
section. The other two parts are “Solutions to Fermi’s Paradox” and
“The Big Picture,” which are optional.

Reading this article should take approximately 15 minutes.

Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above.